init: archlens — architecture diagram generator

Hex arch + DDD, tree-sitter parsing, Mermaid/ASCII output.
Supports Rust + Python. 92 tests. CI, diff, --check for staleness detection.

crates/adapters/mermaid/src/mermaid_renderer.rs

@@ -0,0 +1,266 @@
+use std::collections::{HashMap, HashSet};
+
+use archlens_domain::{
+    CodeElement, CodeGraph, DiagramLevel, DomainError, RelationshipKind, RenderOutput,
+    RenderedFile, Visibility, ports::DiagramRenderer,
+};
+
+pub struct MermaidRenderer {
+    level: DiagramLevel,
+}
+
+impl Default for MermaidRenderer {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl MermaidRenderer {
+    pub fn new() -> Self {
+        Self {
+            level: DiagramLevel::Type,
+        }
+    }
+
+    pub fn with_level(level: DiagramLevel) -> Self {
+        Self { level }
+    }
+
+    fn format_element_name(element: &CodeElement) -> String {
+        let name = element.name();
+        if element.generics().is_empty() {
+            name.to_string()
+        } else {
+            format!("{}~{}~", name, element.generics().join(", "))
+        }
+    }
+
+    fn format_visibility(visibility: Visibility) -> &'static str {
+        match visibility {
+            Visibility::Public => "public",
+            Visibility::Private => "private",
+            Visibility::Internal => "internal",
+        }
+    }
+
+    fn render_class_diagram(&self, graph: &CodeGraph) -> String {
+        let mut lines = vec!["classDiagram".to_string()];
+
+        let mut grouped: HashMap<String, Vec<&CodeElement>> = HashMap::new();
+        let mut ungrouped: Vec<&CodeElement> = Vec::new();
+
+        for element in graph.elements() {
+            if let Some(module) = element.module() {
+                grouped
+                    .entry(module.as_str().to_string())
+                    .or_default()
+                    .push(element);
+            } else {
+                ungrouped.push(element);
+            }
+        }
+
+        let has_namespaces = !grouped.is_empty();
+
+        let mut seen: HashSet<String> = HashSet::new();
+        for element in &ungrouped {
+            if seen.insert(element.name().to_string()) {
+                Self::push_class_lines(&mut lines, element, "    ");
+            }
+        }
+
+        if has_namespaces {
+            for (namespace, elements) in &grouped {
+                lines.push(format!("    namespace {namespace} {{"));
+                let mut ns_seen: HashSet<String> = HashSet::new();
+                for element in elements {
+                    if ns_seen.insert(element.name().to_string()) {
+                        Self::push_class_lines(&mut lines, element, "        ");
+                    }
+                }
+                lines.push("    }".to_string());
+            }
+        }
+
+        let mut rel_seen: HashSet<String> = HashSet::new();
+        for rel in graph.relationships() {
+            if rel.kind() == RelationshipKind::Import {
+                continue;
+            }
+            let arrow = match rel.kind() {
+                RelationshipKind::Inheritance => "<|--",
+                RelationshipKind::Composition => "-->",
+                RelationshipKind::Import => "..>",
+            };
+            let key = format!("{} {} {}", rel.source(), arrow, rel.target());
+            if rel_seen.insert(key.clone()) {
+                lines.push(format!("    {key}"));
+            }
+        }
+
+        lines.join("\n")
+    }
+
+    fn push_class_lines(lines: &mut Vec<String>, element: &CodeElement, indent: &str) {
+        lines.push(format!(
+            "{indent}class {}",
+            Self::format_element_name(element)
+        ));
+        if element.visibility() != Visibility::Public {
+            lines.push(format!(
+                "{indent}<<{}>> {}",
+                Self::format_visibility(element.visibility()),
+                element.name()
+            ));
+        }
+        let name = element.name();
+        for field in element.fields() {
+            lines.push(format!("{indent}{name} : {field}"));
+        }
+        for method in element.methods() {
+            lines.push(format!("{indent}{name} : {method}"));
+        }
+    }
+
+    fn render_module_flowchart(&self, graph: &CodeGraph) -> String {
+        let mut lines = vec!["graph TD".to_string()];
+
+        let mut name_to_modules: HashMap<&str, HashSet<&str>> = HashMap::new();
+        let mut file_to_module: HashMap<String, String> = HashMap::new();
+        let mut modules: HashSet<String> = HashSet::new();
+
+        for element in graph.elements() {
+            if let Some(module) = element.module() {
+                name_to_modules
+                    .entry(element.name())
+                    .or_default()
+                    .insert(module.as_str());
+                modules.insert(module.as_str().to_string());
+
+                let file_stem = std::path::Path::new(element.file_path().as_str())
+                    .file_stem()
+                    .and_then(|s| s.to_str())
+                    .unwrap_or("");
+                if !file_stem.is_empty() {
+                    file_to_module.insert(file_stem.to_string(), module.as_str().to_string());
+                }
+            }
+        }
+
+        for module in &modules {
+            lines.push(format!("    {module}[{module}]"));
+        }
+
+        let mut module_edges: HashSet<(String, String)> = HashSet::new();
+        for rel in graph.relationships() {
+            match rel.kind() {
+                RelationshipKind::Import => {
+                    let source_mod = file_to_module.get(rel.source());
+                    let target_top = rel.target().split('.').next().unwrap_or("");
+                    let target_mod = Self::capitalize(target_top);
+
+                    if let Some(src) = source_mod
+                        && modules.contains(&target_mod)
+                        && *src != target_mod
+                    {
+                        module_edges.insert((src.clone(), target_mod));
+                    }
+                }
+                _ => {
+                    if modules.contains(rel.source())
+                        && modules.contains(rel.target())
+                        && rel.source() != rel.target()
+                    {
+                        module_edges.insert((rel.source().to_string(), rel.target().to_string()));
+                        continue;
+                    }
+
+                    let src_mods = name_to_modules.get(rel.source());
+                    let tgt_mods = name_to_modules.get(rel.target());
+
+                    if let (Some(src_set), Some(tgt_set)) = (src_mods, tgt_mods) {
+                        for src_mod in src_set {
+                            if tgt_set.contains(src_mod) {
+                                continue;
+                            }
+                            for tgt_mod in tgt_set {
+                                if src_mod != tgt_mod {
+                                    module_edges.insert((src_mod.to_string(), tgt_mod.to_string()));
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        for (source, target) in &module_edges {
+            lines.push(format!("    {source} --> {target}"));
+        }
+
+        lines.join("\n")
+    }
+
+    fn capitalize(s: &str) -> String {
+        if s.is_empty() {
+            return String::new();
+        }
+        format!("{}{}", s[..1].to_uppercase(), &s[1..])
+    }
+
+    fn render_project_flowchart(&self, graph: &CodeGraph) -> String {
+        let mut lines = vec!["graph TD".to_string()];
+
+        let mut grouped: HashMap<String, Vec<&CodeElement>> = HashMap::new();
+        let mut ungrouped: Vec<&CodeElement> = Vec::new();
+
+        for element in graph.elements() {
+            if let Some(module) = element.module() {
+                grouped
+                    .entry(module.as_str().to_string())
+                    .or_default()
+                    .push(element);
+            } else {
+                ungrouped.push(element);
+            }
+        }
+
+        for element in &ungrouped {
+            let id = Self::sanitize_id(element.name());
+            lines.push(format!("    {id}[{}]", element.name()));
+        }
+
+        for (group, elements) in &grouped {
+            lines.push(format!("    subgraph {group}"));
+            for element in elements {
+                let id = Self::sanitize_id(element.name());
+                lines.push(format!("        {id}[{}]", element.name()));
+            }
+            lines.push("    end".to_string());
+        }
+
+        for rel in graph.relationships() {
+            let source_id = Self::sanitize_id(rel.source());
+            let target_id = Self::sanitize_id(rel.target());
+            lines.push(format!("    {source_id} --> {target_id}"));
+        }
+
+        lines.join("\n")
+    }
+
+    fn sanitize_id(name: &str) -> String {
+        name.replace(['-', '.'], "_")
+    }
+}
+
+impl DiagramRenderer for MermaidRenderer {
+    fn render(&self, graph: &CodeGraph) -> Result<RenderOutput, DomainError> {
+        let content = match self.level {
+            DiagramLevel::Type => self.render_class_diagram(graph),
+            DiagramLevel::Module => self.render_module_flowchart(graph),
+            DiagramLevel::Project => self.render_project_flowchart(graph),
+        };
+        let file = RenderedFile::new("diagram.mmd", &content)?;
+        Ok(RenderOutput::single(file))
+    }
+}